A gene (amyA) encoding an extracellular α-amylase from a marine bacterium Pseudoalteromonas sp. MY-1 was
cloned and expressed in Escherichia coli. It comprised an open-reading-frame of 2,007 base pairs and encoded a protein of
669 amino acids with a predicted molecular weight of 73,770 daltons and a pI of 5.15. The entire amino acid sequence of
amyA gene showed 86% similarity to the α-amylase preproprotein from Pseudoalteromonas haloplanktis. It consisted of a
signal peptide, α-amylase catalytic domain and an amy C domain. The recombinant amylase was purified to homogeneity
and biochemically characterized. The enzyme revealed maximum activity at pH 7.0 and 40ºC. The enzyme hydrolyzed
soluble starch and some maltooligosaccharides to several oligosaccharides, and maltose was the common product from
different substrates.